Hi
It's
always good to have these questions and learn a little more.
Maybe this type of problem has already been posted here on the forum but you would need to do a deep search
I believe I have found the cause of the problem but not the solution.
I tested the files you mentioned and noticed that they are "too large" to be displayed in the Jam Editor 1.6 tool and these images end up being cut off.
This is due to the Canvas Height size.
Note that these files have "adel_pit.jam = 700", "adel_pt.jam 700", "adel_scaf.jam = 768" and "adel_sign.jam = 600"
When converting from HW to SW the image is cut off and overlapped... and this causes a bug in the texture positions... which is why it does not save.
Jam files that have smaller canvas, this does not happen.
Then I asked myself. Is there a limit for Canvas?
I did more tests and realized that all images (textures) have to be inside the "Jam Convert" screen and if it is bigger the image is cut and sometimes it can be saved and other times it can't because of the Canvas size.
See the comparison between the JAM files


You can see that some even save but the file is missing the bottom part of the textures and these because of the very high CNVAS it won't even let you save
That was the conclusion I reached...
Evandro ( Brazil )